The basic operation and structure of a land mobile radio system is well known. Land mobile radio systems typically comprise one or more radio communication units (e.g., vehicle-mounted or portable radios in a land mobile system and radio/telephones in a cellular system) and one or more repeaters that transceive information via the RF communication resources. These communication resources may be narrow band frequency modulated channels, time division multiplex slots, frequency pairs, and so forth. Land mobile radio systems may be organized as trunked communication systems, where a plurality of communication resources is allocated amongst a group of users by assigning the repeaters on a communication-by-communication basis with an RF coverage area.
Currently, there is a desire to have larger communication systems that cover much larger geographic areas. Today, communication systems are known to be organized into a plurality of communication sites, with a zone or network controller (ZC) attached to a bank of repeaters at each of the plurality of sites so that communication requests from a communication unit within a coverage area may be handled and organized amongst all of the sites that are connected to that zone controller. These repeaters may be intelligent repeaters, such as an IntelliRepeater.TM. available from Motorola, Inc., and the zone controller communicates with the intelligent repeater that is currently in control of the site. Alternatively, the repeaters may be standard repeaters with a site controller attached to the each of the repeaters at the site, and the site controller coordinates resources for the site.
There is, however, a limit to the number of sites that can be serviced by one zone controller. Consequently, a need exists for a way to provide communications over larger areas of land, particularly for a single call over larger areas of land than can be accommodated by today's multiple site systems.